U.S. patent application number 17/160170 was filed with the patent office on 2021-06-03 for biosensor calibration coding systems and methods.
The applicant listed for this patent is Ascensia Diabetes Care Holdings AG. Invention is credited to Igor Gofman.
Application Number | 20210164962 17/160170 |
Document ID | / |
Family ID | 1000005387086 |
Filed Date | 2021-06-03 |
United States Patent
Application |
20210164962 |
Kind Code |
A1 |
Gofman; Igor |
June 3, 2021 |
BIOSENSOR CALIBRATION CODING SYSTEMS AND METHODS
Abstract
A test sensor (100) for determining an analyte concentration in
a biological fluid comprises a strip including a fluid receiving
area (128) and a port-insertion region (126). A first row of
optically transparent (132) and non-transparent positions forms a
calibration code pattern (130) disposed within a first area of the
port-insertion region (126). A second row of optically transparent
(142) and non-transparent positions forms a synchronization code
pattern (140) disposed within a second area of the port-insertion
region (126). The second area is different from the first area. The
synchronization code pattern (140) corresponds to the calibration
code pattern (130) such that the synchronization code pattern (140)
provides synchronization of the serial calibration code pattern
(130) during insertion of the port-insertion region (126) into the
receiving port of the analyte meter.
Inventors: |
Gofman; Igor;
(Croton-on-Hudson, NY) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Ascensia Diabetes Care Holdings AG |
Basel |
|
CH |
|
|
Family ID: |
1000005387086 |
Appl. No.: |
17/160170 |
Filed: |
January 27, 2021 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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16659258 |
Oct 21, 2019 |
10928379 |
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17160170 |
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16420990 |
May 23, 2019 |
10488395 |
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16659258 |
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15123334 |
Sep 2, 2016 |
10330666 |
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PCT/US2015/019020 |
Mar 5, 2015 |
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16420990 |
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61949587 |
Mar 7, 2014 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
G01N 2021/7759 20130101;
G01N 33/49 20130101; G01N 2201/127 20130101; G01N 27/3272 20130101;
G01N 2021/7786 20130101; G01N 21/78 20130101; G01N 27/3274
20130101; G01N 21/8483 20130101; G01N 33/48771 20130101 |
International
Class: |
G01N 33/487 20060101
G01N033/487; G01N 21/84 20060101 G01N021/84; G01N 21/78 20060101
G01N021/78; G01N 27/327 20060101 G01N027/327; G01N 33/49 20060101
G01N033/49 |
Claims
1-28. (canceled)
29. A test sensor comprising: a strip including a fluid-receiving
area and a port-insertion region; one or more sensor contacts at
least partially disposed in the port-insertion region, the one or
more sensor contacts configured to complete a detection circuit
with one or more sensor interfaces of a receiving port of an
analyte meter causing a signal to be received by the analyte meter
to initiate instructions for a pattern read device to begin
transmitting light waves; a row of optically transparent and
non-transparent positions forming a synchronization code pattern
disposed within a first area of the port-insertion region, the
first area being different from another area of the port-insertion
region including a calibration code pattern, wherein the
synchronization code pattern corresponds to the calibration code
pattern such that the synchronization code pattern provides
synchronization of the calibration code pattern during insertion of
the port-insertion region into the receiving port.
30. The test sensor of claim 29, wherein the synchronization code
pattern includes at least one aperture in the strip defining one or
more of the optically transparent positions.
31. The test sensor of claim 29, wherein the synchronization code
pattern has a length, the calibration code pattern having the same
length as the synchronization code pattern.
32. The test sensor of claim 29, wherein the positions forming the
calibration code pattern are disposed linearly on the strip
parallel to the synchronization code pattern.
33. The test sensor of claim 29, wherein the port-insertion region
includes a first edge and an opposing second edge, the calibration
code pattern being oriented parallel to and along the first edge,
the synchronization code pattern being oriented parallel to and
along the second edge.
34. The test sensor of claim 29, wherein the calibration code
pattern and the synchronization code pattern together occupy less
than 0.06 square inches of a top surface of the strip.
35. The test sensor of claim 29, wherein the test sensor is an
optical biosensor.
36. The test sensor of claim 29, wherein the synchronization code
pattern has evenly distributed serial openings each separated by
evenly distributed optically non-transparent material.
37. The test sensor of claim 29, wherein the test includes a
reagent, the reagent including glucose oxidase or glucose
dehydrogenase for determining a glucose concentration in a
biological fluid.
38. A biosensor comprising: a strip including a fluid-receiving
area, a port-insertion region, and one or more electrical contacts
at least partially disposed within the port-insertion region, the
electrical contacts configured to configured complete a detection
circuit with one or more sensor interfaces of a receiving port of
an analyte meter causing a signal to be received by the analyte
meter to initiate instructions for a pattern read device to begin
transmitting light waves; and a synchronization code pattern
disposed within a first area of the port-insertion region that is
different from a second area containing a serial calibration code
pattern, the synchronization code pattern including optically
transparent portions allowing light waves to be transmitted
therethrough, wherein the synchronization code pattern provides
synchronization of the serial calibration code pattern during
insertion of the port-insertion region into the receiving port.
39. The biosensor of claim 38, wherein the synchronization code
pattern has evenly distributed serial openings each separated by
evenly distributed optically non-transparent material.
40. The biosensor of claim 38, wherein the biosensor includes a
reagent, the reagent including glucose oxidase or glucose
dehydrogenase for determining a glucose concentration in a
biological fluid.
41. The biosensor of claim 38, wherein the calibration code pattern
and the synchronization code pattern together occupy less than 0.06
square inches of a top surface of the strip.
42. The biosensor of claim 38, wherein the biosensor is an optical
biosensor.
43. The biosensor of claim 38, wherein the calibration code pattern
has a length, the synchronization code pattern having the same
length as the calibration code pattern.
44. The biosensor of claim 38, wherein the positions forming the
calibration code pattern are linearly disposed on the strip
parallel to the synchronization code pattern.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. application Ser.
No. 16/659,258, filed Oct. 21, 2019, now allowed, which is a
continuation of U.S. application Ser. No. 16/420,990, filed May 23,
2019, now U.S. Pat. No. 10,488,395, which is a divisional of U.S.
application Ser. No. 15/123,334, filed on Sep. 2, 2016, now U.S.
Pat. No. 10,330,666, which is a U.S. National Stage of
International Application No. PCT/US2015/019020, filed Mar. 5,
2015, which claims priority to and the benefits of U.S. Patent
Application No. 61/949,587, filed Mar. 7, 2014, the contents of
each of which are hereby incorporated by reference herein in their
entireties.
FIELD OF THE INVENTION
[0002] The present invention generally relates to biosensors for
determining analyte concentration of a fluid sample, and more
particularly, to systems and methods of serial coding of biosensors
to calibrate instruments that determine an analyte concentration of
a fluid sample.
BACKGROUND OF THE INVENTION
[0003] The quantitative determination of analytes in body fluids is
of great importance in the diagnoses and maintenance of certain
physiological conditions. For example, lactate, cholesterol, and
bilirubin should be monitored in certain individuals. In
particular, determining glucose in body fluids is important to
individuals with diabetes who must frequently check the glucose
level in their blood to regulate the carbohydrate intake in their
diets. The results of such tests can be used to determine what, if
any, insulin or other medication needs to be administered. In one
type of testing system, test sensors are used to test a fluid such
as a sample of blood.
[0004] A test sensor contains biosensing or reagent material that
reacts with blood glucose. The testing end of the sensor is adapted
to be placed into the fluid being tested, for example, blood that
has accumulated on a person's finger after the finger has been
pricked. The fluid is drawn into a capillary channel that extends
in the sensor from the testing end to the reagent material by
capillary action so that a sufficient amount of fluid to be tested
is drawn into the sensor. The fluid then chemically reacts with the
reagent material in the sensor and the system correlates this to
information relating an analyte (e.g., glucose) in a fluid
sample.
[0005] Diagnostic systems, such as blood-glucose testing systems,
typically calculate the actual glucose value based on a measured
output and the known reactivity of the reagent-sensing element
(test sensor) used to perform the test. The reactivity or
lot-calibration information of the test sensor may be given to the
user in several forms including a number or character that they
enter into the instrument. One method includes using an element
that is similar to a test sensor, but which was capable of being
recognized as a calibration element by the instrument. The test
element's information is read by the instrument or a memory element
that is plugged into the instrument's microprocessor board for
directly reading the test element.
[0006] There is an ongoing need for improved biosensors, especially
those that may provide increasingly accurate and/or precise analyte
concentration measurements. The systems, devices, and methods of
the present invention overcome at least one of the disadvantages
associated with encoding patterns on sensor strips used in
biosensors.
SUMMARY OF THE INVENTION
[0007] According to one aspect of the present invention, a test
sensor for determining an analyte concentration in a biological
fluid comprises a strip including a fluid receiving area and a
port-insertion region. A first row of optically transparent and
non-transparent positions forms a calibration code pattern disposed
within a first area of the port-insertion region. A second row of
optically transparent and non-transparent positions forms a
synchronization code pattern disposed within a second area of the
port-insertion region. The second area is different from the first
area. The synchronization code pattern corresponds to the
calibration code pattern such that the synchronization code pattern
provides synchronization of the serial calibration code pattern
during insertion of the port-insertion region into the receiving
port of the analyte meter.
[0008] According to another aspect of the present invention, a test
sensor for determining an analyte concentration in a biological
fluid comprises a strip including a fluid-receiving area and a
port-insertion region. One or more electrical contacts are at least
partially disposed within the port-insertion region. The electrical
contacts are configured to align and electrically connect with
sensor contacts of an analyte meter upon insertion of the
port-insertion region into a receiving port of the analyte meter. A
serial calibration code pattern is disposed within a first area of
the port-insertion region. The serial calibration code pattern
includes first optically transparent portions allowing light waves
to be transmitted therethrough. A synchronization code pattern is
disposed within a second area of the port-insertion region. The
second area is different from the first area. The synchronization
code pattern includes second optically transparent portions
allowing light waves to be transmitted therethrough. The
synchronization code pattern corresponds to the serial calibration
code pattern such that the synchronization code pattern provides
synchronization of the serial calibration code pattern during
insertion of the port-insertion region into the receiving port of
the analyte meter.
[0009] According to another aspect of the present invention, a
biosensor system for determining an analyte concentration in a
biological fluid comprises a measurement device including a
processing unit connected to an optical pattern read device. The
optical pattern read device includes one or more light sources, a
first light sensor, and a second light sensor. A sensor strip
includes sequential data coding patterns including first optically
transparent openings and separate corresponding synchronization
coding patterns including second optically transparent openings.
The one or more light sources are configured to transmit light
waves through the first and second optically transparent openings.
The one or more light sources are at least partially positioned on
a first side of the first and second optically transparent
openings. The first light sensor is positioned on an opposite side
of the first optically transparent openings and the second light
sensor is positioned on an opposite side of the second optically
transparent openings. The first light sensor and the second light
sensor are configured to receive transmitted light waves from the
one or more light sources. The light waves are transmitted by the
one or more light sources and received by the first light sensor
and the second light sensor while the sensor strip is being
inserted into the measurement device such that light waves received
by the second light sensor associated with the synchronization
coding patterns provide synchronization for the light waves
received by the first light sensor associated with the sequential
data coding patterns.
[0010] According to yet another aspect of the present invention, a
method for calibrating an analysis of an analyte in a biological
fluid. The method includes the following acts: (a) transmitting
light waves through first optically transparent openings in a test
sensor including a first row of sequential optically transparent
and non-transparent positions forming calibration coding patterns;
(b) near simultaneous to act (a), transmitting light waves through
second optically transparent openings in the test sensor including
a second row of sequential optically transparent and
non-transparent positions forming synchronization coding patterns
that correspond to the calibration coding patterns; (c) receiving
the light waves transmitted through the first optically transparent
openings in a first light sensor; (d) receiving the light waves
transmitted through the second optically transparent openings in a
second light sensor; (e) generating a series of calibration code
signals in response to light waves being received and not received
by the first light sensor due to the optically transparent and
non-transparent positions passing the first light sensor during the
insertion of the test sensor into the analyte measuring device; (f)
near simultaneous to act (e), generating a series of
synchronization code signals in response to light waves being
received and not received by the second light sensor due to the
second row of sequential optically transparent and non-transparent
positions passing the second light sensor during the insertion of
the test sensor into the analyte measuring device, the series of
synchronization code signals corresponding to the series of
calibration code signals; (g) calibrating at least one correlation
equation in response to the series of calibration code signals; and
(h) determining an analyte concentration in response to the at
least one calibrated correlation equation. The analyte
concentration is determined by reacting the analyte in an
electrochemical reaction that produces an output signal. The
analyte concentration is calculated using the at least one
calibrated correlation equation and the produced output signal.
[0011] Additional aspects of the invention will be apparent to
those of ordinary skill in the art in view of the detailed
description of various embodiments, which is made with reference to
the drawings, a brief description of which is provided below.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1 illustrates a top view of a sensor strip with serial
optical coding according to one embodiment.
[0013] FIG. 2 illustrates a side view of a portion of the sensor
strip in FIG. 1 along with aspects of an optical pattern read
device according to one embodiment.
[0014] FIG. 3 illustrates a top view of a sensor strip with serial
optical coding inserted into a sensor interface and optical pattern
read device according to one embodiment.
[0015] FIG. 4 illustrates a side view of the sensor strip in FIG. 3
according to one embodiment.
[0016] FIG. 5 illustrates a sensor strip adjacent to a sensor
interface and optical pattern read device along with code and
synchronization signals generated by the insertion of the sensor
strip into the sensor interface.
[0017] FIG. 6 illustrates another aspect of the code and
synchronization signals generated by the insertion of the sensor
strip into the sensor interface.
[0018] FIGS. 7 and 8 illustrate sensor strips including optically
transparent serial data coding patterns and synchronization coding
patterns created by punching apertures into the sensor strip
according to certain embodiments.
[0019] FIG. 9 illustrates a sensor strip including optically
transparent serial data coding patterns and synchronization coding
patterns created by placing printed coding patterns on a
transparent area of the sensor strip according to one
embodiment.
[0020] FIG. 10 is a flowchart of an exemplary method for
calibrating an analysis of an analyte in a fluid sample according
to certain embodiments.
[0021] While the invention is susceptible to various modifications
and alternative forms, specific embodiments are shown by way of
example in the drawings and are described in detail herein. It
should be understood, however, that the invention is not intended
to be limited to the particular forms disclosed. Rather, the
invention is to cover all modifications, equivalents, and
alternatives falling within the spirit and scope of the
invention.
DETAILED DESCRIPTION
[0022] While this invention is susceptible of embodiment in many
different forms, there is shown in the drawings and will herein be
described in detail preferred embodiments of the invention with the
understanding that the present disclosure is to be considered as an
exemplification of the principles of the invention and is not
intended to limit the broad aspect of the invention to the
embodiments illustrated. For purposes of the present detailed
description, the singular includes the plural and vice versa
(unless specifically disclaimed); the word "or" shall be both
conjunctive and disjunctive; the word "all" means "any and all";
the word "any" means "any and all"; and the word "including" means
"including without limitation."
[0023] The present disclosure relates to improvements in sensors
(e.g., sensor strips, biosensors, test sensors) for systems for
determining analyte concentrations in fluid samples, such as
biological samples (e.g., blood glucose samples). Sensors are used
to collect analyte samples, such as fluid samples (e.g., blood
sample, other biological fluid samples), and are inserted into an
analyte concentration measurement device (e.g., blood glucose
meter) where signals may be applied to the sample via the sensors
as part of determining an analyte concentration of the fluid
sample. Sensors are typically manufactured in batches that are
calibrated at a manufacturing facility. Coding information may be
applied to a sensors that can be read by or otherwise determined by
an analyte concentration measurement device (e.g., blood glucose
meter). In some aspects, the calibration information is received by
the device following the insertion of the sensor into the
measurement device that applies the test signal to the sample that
was received on the sensor.
[0024] Calibration information can be used to adjust the analysis
of the analyte concentration determination in response to one or
more calibration parameters (e.g., manufacturing variations, sensor
expiration date) that are encoded onto a sensor and read by an
analyte concentration measurement device. A desirable aspect of the
present disclosure is the ability to improve the accuracy of an
analyte concentration measurement by allowing an increased amount
of calibration information to be encoded onto a sensor. The
increased amount of calibration information can then be read by the
measurement device after a sensor is inserted into a sensor
connector or sensor interface of the measurement device where an
increased number of calibration codes are read and processed to
correct a stored equation associated with a determination of an
analyte concentration of a fluid sample. The calibration codes are
specific to and present on the sensor itself and can further
include calibration parameters that take into account, for example,
manufacturing variations, sensor strip expiration information, and
other aspects that can be corrected for when determining an analyte
concentration of a fluid sample.
[0025] Sensors, such as those used to test biological fluid samples
(e.g., blood) can include generally rectangular dimensions ranging
anywhere from about 0.1 to 0.5 inches (about 2.5 to 12.7 mm) wide
by about 0.5 to 1.5 inches (about 12 to 38 mm) long. In some
aspects, a top surface area of a flat test sensor can range
anywhere from about 0.05 to 0.75 square inches (about 30 to 483
mm.sup.2). Sensors typically include a fluid-receiving area and an
area with contacts for electrically connecting the sensor to the
analyte concentration measurement device. Based on the relatively
small size of sensors for biological fluid sampling, such as
sensors for determining blood glucose concentrations, there is a
very limited amount of space to encode a sensor with calibration
information that can be read from the sensor and used in
determining an analyte concentration.
[0026] The application of parallel code patterns can be used for
small surface areas on certain sensor strips. However, parallel
coding has only a limited number of code variations (e.g.,
typically about eight for a sensor strip for biological fluids such
as blood). Furthermore, parallel coding requires the insertion of
the entire coding pattern into a sensor port of a measurement
device so that the entire pattern is read at the same time. Serial
code patterns can also be used and provide a higher number of code
variations (e.g., up to fifteen for a sensor strip for biological
fluids such as blood) than are typically available for parallel
coding. However, serial coding typically requires a significant
amount of space relative to the limited surface area available for
coding on a test sensor, such as a typical test sensor used for
biological fluid samples (e.g., blood glucose samples). For
example, to increase the number of code variations using serial
coding (e.g., more than fifteen), the length of a sensor strip
would need to increase and a larger sensor port on a measurement
device would be needed. It would be desirable to encode a sensor
strip with a large number of different calibration codes to allow
for greater accuracy of analyte concentration determinations, while
limiting the area needed on a sensor strip to accommodate the
calibration coding patterns. The present disclosure provides the
ability to implement hundreds and even thousands of calibration
codes within the very limited space of a sensor strip using optical
methods where optically transparent coding patterns can be read
with an optical pattern reading device. By allowing a larger number
of calibration codes, the accuracy of analyte concentration
measurements is increased as more factors can be used to correct
the equation for calculating an analyte concentration. An increase
in calibration codes allows for more sensor specific corrections
such as variations in manufacturing or other sensor-specific
factors (e.g., reagent characteristics, expiration date of sensor,
batch number corrections) that, uncorrected, can cause a decrease
in the accuracy of analyte concentration determinations.
[0027] Turning now to FIGS. 1 and 2, a top view and side view of an
exemplary biosensor 100 (e.g., test sensor, sensor strip) is
illustrated that includes calibration coding. The exemplary
biosensor 100 is depicted as a generally flat, elongated strip,
though other shapes are contemplated (e.g., forked end, tapered
end, trapezoidal portions, combinations of shapes). The biosensor
includes a fluid-receiving area 128 and a port-insertion region
126. The fluid-receiving area 128 includes a channel 124 configured
to receive fluid samples, such as sample of a biological fluid. The
channel 124 may be sized such that capillary action pulls the fluid
sample into the channel of the fluid-receiving area 128. The
received fluid sample can then be tested to determine an analyte
concentration using an instrument or meter after the port-insertion
region 126 of the biosensor 100 is inserted into the instrument or
meter.
[0028] It is contemplated that the non-limiting exemplary sensors
described herein (e.g., biosensor 100) may be electrochemical test
sensors. In such embodiments, an analyte meter may have mechanical
or optical aspects so as to detect the calibration information and
electrochemical aspects to determine the analyte concentration of
the fluid sample. While only a top view of the biosensor is
illustrated in FIG. 1, such biosensors can include a base and a
second layer (e.g., a lid) that assist in forming the channel 124.
The biosensor 100 may also include a plurality of electrodes (not
shown) such as a counter electrode, a working electrode, a trigger
electrode, an underfill detection electrode, or a hematocrit
electrode in the fluid-receiving area 128. The electrodes are
coupled to conductive leads (not shown) that extend from the
fluid-receiving area 128 to biosensor contacts 122a, 122b in the
port-insertion region 126. The electrodes may be at least partially
embedded between the base and lid and the conductive leads may
extend within the base and lid of the biosensor from the electrodes
to biosensor contacts 122a, 122b in the port-insertion region. It
is contemplated that electrochemical test sensors other than those
illustrated may be employed.
[0029] The fluid-receiving area 128 includes at least one reagent
for converting the analyte of interest (e.g., glucose) in the fluid
sample (e.g., blood) into a chemical species that is
electrochemically measurable, in terms of the electrical current it
produces, by the components of the electrode pattern. The reagent
typically contains an enzyme such as, for example, glucose oxidase,
which reacts with the analyte and with an electron acceptor such as
a ferricyanide salt to produce an electrochemically measurable
species that can be detected by the electrodes. It is contemplated
that other enzymes may be used to react with glucose such as
glucose dehydrogenase. If the concentration of another analyte is
to be determined, an appropriate enzyme is selected to react with
the analyte.
[0030] A fluid sample (e.g., blood) may be applied to the
fluid-receiving area 128 at or near channel 124. The fluid sample
travels through the channel where it then reacts with the at least
one reagent. After reacting with the reagent and in conjunction
with the plurality of electrodes, the fluid sample produces
electrical signals that assist in determining the analyte
concentration. The conductive leads carry the electrical signal
back toward a second opposing end of the biosensor 100, such as the
port-insertion region 126, where the biosensor contacts 122a, 122b
transfer the electrical signals into the meter when the biosensor
is inserted into the meter.
[0031] As discussed above, a sensor may analyze the analyte in a
sample using an electrochemical analysis. It is also contemplated
that a sensor may analyze the analyte in a sample using an optical
analysis or a combination of optical and electrochemical methods.
As discussed above, during electrochemical analyses, an excitation
signal is applied to the sample of the biological fluid. The
excitation signal may be a potential or current and may be
constant, variable, or a combination thereof. The excitation signal
may be applied as a single pulse or in multiple pulses, sequences,
or cycles. Various electrochemical processes may be used such as
amperometry, coulometry, voltammetry, gated amperometry, gated
voltammetry, and the like.
[0032] Optical test sensor systems may use techniques, such as
transmission spectroscopy, diffuse reflectance, spectroscopy, or
fluorescence spectroscopy, for measuring the analyte concentration.
An indicator-reagent system and an analyte in a sample of body
fluid are reacted to produce a chromatic reaction, as the reaction
between the reagent and analyte causes the sample to change color.
The degree of color change is indicative of the analyte
concentration in the body fluid.
[0033] An optical test sensor can include auto-calibration
information and a sample-receiving area (e.g., fluid-receiving
area). The sample-receiving area includes an indicator-reagent
system that is adapted to produce a chromatic reaction after being
exposed to an analyte in a fluid sample. The reagent may be dried
and then mixed with the sample in the sample-receiving area.
Alternatively, the reagent may be deposited with the sample or
after the sample has been received in the sample-receiving
area.
[0034] An optical analysis generally measures the amount of light
absorbed or generated by a reaction of a chemical indicator with an
analyte. An enzyme may be included with the chemical indicator to
enhance the reaction kinetics. The light from an optical system may
be converted into an electrical signal such as current or potential
by a detector.
[0035] In light-absorption optical analyses, a chemical indicator
produces a reaction product that absorbs light. An incident
excitation beam from a light source is directed toward the sample.
The incident beam may be reflected back from or transmitted through
the sample to a detector or sensor. The detector collects and
measures the attenuated incident beam. The amount of light
attenuated by the reaction product is an indication of the analyte
concentration in the sample.
[0036] In light-generated optical analyses, the chemical indicator
produces a reaction product that fluoresces or emits light in
response to the analyte during the redox reaction. A detector
collects and measures the generated light. The amount of light
produced by the chemical indicator is an indication of the analyte
concentration in the sample.
[0037] A biosensor can be made from a variety of materials such as
polymeric materials. Non-limiting examples of polymeric materials
that may be used to form a base, a lid, and any spacers of a
biosensor include polycarbonate, polyethylene terephthalate (PET),
polyethylene naphthalate (PEN), polyimide, and combinations
thereof. It is contemplated that other materials may be used in
forming a biosensor base, lid, and/or spacer.
[0038] To form the biosensor, the base, the spacer, and the lid are
attached by, for example, an adhesive or heat sealing. When the
base, the lid, and/or the spacer are attached, the fluid-receiving
area 128 and channel 124 are formed. The fluid-receiving area 128
provides a flow path for introducing the fluid sample into the
biosensor.
[0039] The exemplary biosensor 100 depicted in FIG. 1 also includes
a serial calibration code pattern 130 disposed generally along a
first side 112 of the biosensor 100. The serial calibration code
pattern 130 includes optically transparent portions (e.g., 132)
that allow light waves to be transmitted therethough. The biosensor
100 further includes a synchronization code pattern 140 disposed
generally along a second side 114 of the biosensor 100. The
synchronization code pattern 140 also includes optically
transparent portions (e.g., 142) that allow light waves to be
transmitted therethrough with optically transparent openings being
generally evenly spaced along the pattern 140 with optically
non-transparent portions in between. While the serial calibration
code pattern 130 and the synchronization code pattern 140 are
depicted as two parallel strings on two opposing sides 112, 114 of
the biosensor 100, it is contemplated that the strings can be
offset from each other or even located adjacent to each other with
at least some separation or barrier between the respective patterns
130, 140 as long as the synchronization code pattern 140
corresponds to the serial calibration code pattern 130. The
correspondence between these two patterns 130, 140 provides
synchronization of the serial calibration code pattern 130 during
insertion of the port-insertion region 126 into a receiving port of
an analyte meter, which will be discussed in more detail below
including in the context of FIGS. 2-6.
[0040] The benefit of combining a serial calibration code pattern
with a corresponding synchronization code pattern on a sensor is
that a large number of different calibration codes can be encoded
onto the sensor within a limited area allowing the test sensor size
to remain relatively unchanged while still allowing the sampling of
a biological fluid and insertion of the sensor into an analyte
measurement meter. For example, the non-limiting embodiment of
biosensor 100 and variations thereof allows for anywhere from
hundreds to thousands of calibration codes within the very limited
space of the biosensor 100 through the use of the optically
transparent coding patterns that can be read with an optical
pattern reader associated with the analyte measurement meter. The
illustrated sixteen optically transparent synchronization openings
along pattern 140, allow up to 65.536 (i.e., 2 to the 16.sup.th
power assuming the meter is operating in binary) different
calibration codes can be available for applying a correction to an
analyte concentration determination. If only half the
synchronization openings were used, up to 256 (i.e., 2 to the
8.sup.th power assuming the meter is operating in binary) different
calibration codes would be available. Similarly, if only a quarter
of the synchronization openings were used, up to 16 (i.e., 2 to the
4.sup.th power assuming the meter is operating in binary) different
calibration codes would be available. Thus, the number of
calibration codes that are available is exponentially related to
the number of synchronization openings disposed on the sensor.
While providing what could be nearly an unlimited number of
calibration codes using serial calibration coding methods, the
addition of synchronization coding allows this to be done within
the same amount of surface area on a sensor strip that would
normally be occupied by parallel coding methods. A significant
increase in the number of available calibration codes increases the
accuracy and precision of analyte concentration measurements.
[0041] A biosensor can include at least a portion of the serial
calibration code pattern or at least a portion of the
synchronization code pattern being formed by apertures or holes
(e.g., 132, 142) in the test sensor material. The patterns may also
be formed using optically transparent materials separated by
non-transparent portions. For the synchronization code patterns,
the apertures or optically transparent opening are arranged in an
evenly spaced manner in serial fashion as illustrated, for example,
in synchronization code pattern 140 where the synchronization code
pattern has evenly distributed openings each separated by evenly
distributed optically non-transparent material. The evenly spaced
synchronization code patterns act as clock pulses that are
synchronized with the calibration coding pattern. The calibration
code patterns can also include apertures or optically transparent
materials arranged in a serial fashion on the sensor, but may not
be evenly spaced and may include a series of larger apertures or
optically transparent openings separated by non-transparent
portions to create the pattern associated with a calibration code.
The patterns can be read using an optical pattern reader. In
certain aspects, the serial calibration and synchronization code
patterns each have a certain length that is determined by the
combination of the optically non-transparent portions and the
optically transparent openings that in combination comprise the
calibration or synchronization pattern. In some aspects, depending
on how the two patterns correspond to each other for
synchronization purposes, the synchronization code pattern on the
sensor may be approximately the same length as the serial
calibration code pattern.
[0042] As illustrated in FIG. 1, the serial calibration code
pattern 130 can be disposed on the sensor parallel to the
synchronization code pattern 140. In FIG. 1, the patterns 130, 140
are disposed on opposing sides 112, 114 of the test sensor. The
serial calibration code pattern is disposed on the sensor parallel
to and physically separated from the synchronization code pattern
by an optically non-transparent portion of the sensor. However, it
is contemplated that the code patterns 130, 140 can be disposed at
other locations on the test sensor so long at the synchronization
code pattern corresponds to the calibration code pattern.
[0043] In some aspects, it is contemplated that a test sensor can
include a port-insertion region having a first side and an opposing
second side. The serial calibration code pattern can be oriented
parallel to and along the first side (e.g., an edge of the sensor),
and the synchronization code pattern can be oriented parallel to
and along the second side (e.g., another edge of the sensor). In
certain aspects, the serial calibration code pattern and the
synchronization code pattern each include apertures disposed in the
strip along the first side and the second side. Each of the
apertures of the code patterns may be generally rectangular with
all the sides of the apertures (or in some instances less than all
the sides--e.g., only three sides of the apertures) being defined
by the test sensor.
[0044] The surface area of the test sensor that is occupied by
calibration and synchronization code patterns, while still
providing a large number of calibration codes, can be minimized by
applying the features described by the present disclosure. For a
configuration that provides for up to approximately 65,536
calibration codes, the serial calibration code pattern in some
aspects occupies less than 0.04 square inches of a top surface area
of the sensor. In some aspects, the serial calibration code pattern
occupies less than 0.02 square inches of a top surface area of the
sensor. In some aspects, the synchronization code pattern occupies
less than 0.04 square inches of a top surface area of the sensor.
In some aspects, the synchronization code pattern occupies less
than 0.02 square inches of a top surface area of the sensor. In
some aspects, the serial calibration code pattern and the
synchronization code pattern together occupy less than 0.06 square
inches of a top surface area of the sensor. In certain aspects, the
serial calibration code pattern and the synchronization code
pattern together occupy less than 0.03 square inches of a top
surface area of the sensor.
[0045] Referring now to FIG. 2, an exemplary side view of the
biosensor 100 is depicted along with an artificial light source 160
and light sensor 170 that may be part of an optical pattern reader
used to obtain data encoded onto the biosensor 100. In some
aspects, it is contemplated that the artificial light source 160
may be a light-emitting diode (LED) or another light source that is
known for optical readers in the field of analyte concentration
testing. It is contemplated that the light sensor 170 can be a
photosensor, an array of light detectors, or another
light-sensitive sensor that is known for optical readers in the
field of analyte concentration testing.
[0046] The test sensor can include a plurality of apertures (e.g.,
132, 142) that form the coding patterns. The apertures (e.g., 142)
are depicted as clear (unhatched) areas in the side view of FIG. 2.
The synchronization code pattern 140 illustrate in FIG. 1 and the
cross-sectional view illustrated in FIG. 2 shows a plurality of
synchronization code apertures where each of the apertures are
evenly spaced and correspond to the calibration code pattern (e.g.,
130) illustrated in FIG. 1. The correspondence between the two
patterns is illustrated and described in more detail with respect
to FIG. 6. One non-limiting example of a calibration code pattern
130 is shown in FIG. 1 with less than all of the potential
apertures that could be coded onto the sensor. The selection of
which apertures to form for the calibration code pattern determines
the calibration code conveyed to the meter or instrument, which is
associated with sensor-specific calibration information.
[0047] The apertures 132, 142 may be formed by cutting or punching
of a test sensor. The cutting or punching may be performed by
lasers, mechanical punching, die cutting or by using water jets.
The shape of the apertures 132, 142 is shown as being a thin
generally rectangular slit. Other shapes are contemplated by the
present disclosure includes shapes different from the generally
rectangular shapes, such as those depicted in FIGS. 1-9.
[0048] It is contemplated that a plurality of optically transparent
openings (e.g., 132, 142), such as an aperture, are combined to
form the respective coding patterns. The optically transparent
openings can include an aperture extending entirely through a
sensor (e.g., 100), a transparent opening formed from an optically
transparent material extending through the sensor, or through a
combination apertures partially extending through a sensor and a
remaining portion of optically transparent material. An optically
transparent opening allows light to be transmitted through and
detected on the opposing side of the sensor. Non-limiting examples
of optically clear or translucent material that may be used include
"white" or clear polyethylene terephthalate (PET), "white" or clear
polycarbonate, or "white" or clear glycol-modified PET (PETG).
Alternatively, an optically clear substrate may be covered with an
opaque coating that is then selectively removed to form optically
transparent openings. Examples of such opaque coatings are metals,
such as aluminum, gold or copper formed by vacuum deposition,
sputtering or plating, and carbon, which may be coated or
printed.
[0049] The light source 160 illustrated in FIG. 2 can be part of an
optical pattern read device that includes one or more of the light
sources and a plurality of light sensors (e.g., 170). The
artificial light source 160 can include a light-emitting diode (or
other type of light) 162 that may be covered by a light mask 164
shaped to direct light generated by the LED through a narrow mask
opening 168, and into the optically transparent openings defining
the codes, such that a light beam 180 from the light source is
received by the light sensor 170. The light sensor 170 can include
a photosensor 172 or other light sensing element that may be
covered by a sensor mask 174 that may further include a narrow
light receiving opening 178. The use of masks 168, 178 can be
beneficial for directing the light beam 180 directly into an
optically transparent code opening and also for minimizing or
preventing the receipt of any errant light from another light
source that might give a false positive detection by the light
sensor 170. The masks can also be configured, at least for the
light source, so that the emitted light beam is narrower than the
smallest dimension of the optically transparent openings (e.g.,
apertures). While FIG. 2 illustrates a cross-section through a
synchronization code pattern, the light source and light sensor
features and the aspects of transmitting light through an optically
transparent opening (e.g., 132, 142) is generally the same for both
the synchronization and calibration code patterns.
[0050] The artificial light source 160 and light sensor 170 may be
part of a biosensor system for determining an analyte concentration
in a biological fluid. The biosensor system may include a
measurement device including a processing unit connected to an
optical pattern read device. The optical pattern read device can
include one or more light sources and a plurality of light sensors.
A sensor strip, such as sensor 100 illustrated in FIGS. 1 and 2,
includes sequential data coding patterns including first optically
transparent openings (e.g., 132, 142) and separate corresponding
synchronization coding patterns including second optically
transparent openings. The one or more light sources (e.g., 160) can
be configured to transmit light waves through the first and second
optically transparent openings (e.g., 142). The one or more light
sources are at least partially positioned on a first side of the
first and second optically transparent openings. One of the
plurality of light sensors (e.g., 170) is positioned on an opposite
side of the first optically transparent openings (e.g., 132) and
another of the plurality of light sensors is positioned on an
opposite side of the second optically transparent openings (e.g.,
142). The light sensors (e.g., 170) are configured to receive
transmitted light waves from the one or more light sources. The
light sensors generate a sequence of pulses in response to the
light waves or light beams being transmitted through the optically
transparent openings associated with the sequential data coding
patterns and the synchronization coding patterns.
[0051] In some aspects, the one or more artificial light sources
may be just a single light source (e.g., 160). A plurality of light
guides (not shown) can be employed to receive light from an LED
light (e.g., 162) and redirect the light beam from the light to the
optically transparent openings. One light guide can direct the
light beam to the calibration code pattern and another light guide
can direct the split light beam to the synchronization code
pattern. The light beams are directed by total internal reflection
within the plurality of light guides. It is also contemplated that
the light beams may further be redirected by reflecting surfaces
present in the light guide(s). The plurality of light guides can
further be configured to emit light beams narrower than the
smallest dimension of the optically transparent openings.
[0052] In some aspects, the one or more light sources may include
two light sources (e.g., LEDs). One light may be positioned to
transmit light waves through first optically transparent openings
and into the first light sensor that may be associated with the
serial calibration code patterns. The other light may be positioned
to transmit a light beam through the second optically transparent
openings and into the second light sensor associated with the
serial synchronization code patterns.
[0053] Turning now to FIGS. 3 and 4, a top view and a side view are
illustrated of a sensor strip 300 with serial optical coding that
is inserted into a sensor interface 390 including an optical
pattern read device 380. The sensor 300 includes a port-insertion
region 326 and a fluid-receiving area 328. The port-insertion
region 326 of the sensor 300 can be inserted into the sensor
interface 390 as illustrated in FIGS. 3 and 4. As the sensor 300 is
inserted into the sensor interface 390, sensor detection contacts
394a, 394b will complete a circuit as contact 394b is pushed up and
touches contact 394a to complete the detection circuit. A first end
396 of a sensor detection contact 394b can be positioned at the
portion of the sensor interface where the sensor is first inserted
and before the sensor is placed below the optical pattern reader.
The completion of the circuit between contacts 394a and 394b causes
a signal to be received in a controller or other processing unit
that initiates instructions for the optical pattern read device 380
to begin transmitting light from light source(s) 360 to light
sensor(s) 370 as the sensor 300 is inserted into the sensor
interface. The transmitting and receiving of light is configured to
occur as the calibration code patterns and corresponding
synchronization code patterns pass through the light beam created
by the light source-light sensor arrangement.
[0054] As the sensor 300 is inserted into the sensor interface, the
code pattern is read by the optical pattern read device so that a
calibration code can be determined for use in an equation for
determining an analyte concentration for a fluid sample received in
the fluid-receiving area. The sensor 300 includes contacts 312a,
312b that complete a circuit with sensor interface contacts 392a,
392b, which are used to electrochemically determine a value
associated with an analyte concentration for the received fluid
sample in the fluid-receiving area 328. The sensor interface may be
associated with or be a part of a measurement device in a biosensor
system for determining an analyte concentration in a biological
fluid. For example, the sensor interface may be a part of a blood
glucose meter or another analyte meter and comprise all or a
portion of a sensor receiving area of such meters.
[0055] In some aspects, it is contemplated that a sensor strip
detection system detects a sensor strip being inserted into a port
of a measurement device, such as an analyte meter. The sensor strip
is detected by the detection system immediately prior to commencing
the optical reading of the sequential or serial data coding
patterns and the synchronization coding patterns.
[0056] An optical pattern read device (e.g., 380) including light
sources (e.g., 160, 360) and light sensors (e.g., 170, 370) are
configured to measure optical transmissions through an array of
fine optically transparent openings for the serial calibration and
synchronization codes disposed in a biosensor. In some aspects, and
as illustrated for example in FIGS. 2 and 4, the light sensor (or
light receiver) is disposed on the opposite side of a sensor from
where the light beam generated by the artificial light source first
enters the optically transparent opening in the sensor. It is
contemplated that similar arrangements of the artificial light
source and light sensor are applicable for reading both the serial
synchronization code patterns and the serial calibration code
patterns on a sensor. As illustrated by the non-limiting embodiment
of FIGS. 3 and 4, as the sensor is moving or inserted into a port
or sensor interface, the light sensor (e.g., 370) generates a
sequence of pulses in response to the receipt or lack thereof of
artificial light beams transmitted from the light source. The
receipt of an artificial light beam by the sensor occurs in when an
optically transparent opening (e.g., aperture associated with
coding) is present between the light source and receiver. The lack
of receipt of artificial light occurs when an optically
non-transparent portion is disposed on the sensor, for example
between two optically transparent openings, and blocks a light beam
from being received by the light sensor.
[0057] It is contemplated that the optical pattern read device may
include a microcontroller (or be associated with a microcontroller
or another processing unit) that processes the data pulses to
determine the calibration code for the test sensor. The received
calibration data pulses correspond with the synchronization pulses
to allow for a large number of calibration codes to be available in
a limited space. For example, while a sensor strip is being
inserted into the measurement device, light waves or light beams
may be transmitted by both the first and second light sources and
received by a first light sensor associated with serial or
sequential calibration code patterns and a second light sensor
associated with serial or sequential synchronization code patterns.
The light waves or light beam received by the second light sensor
provides synchronization for the light waves received by the first
light sensor.
[0058] Turning now to FIGS. 5 and 6, a non-limiting top view of an
exemplary sensor strip 500 is depicted adjacent to a sensor
interface 590 having optical read features such as a calibration
light source 580 and a synchronization light source 560, each
having respective sensors (not shown) opposite the light source
with a small gap therebetween to allow for passage of the sensor,
and more specifically, passage of the respective exemplary serial
calibration code pattern 530 and exemplary serial synchronization
code pattern 540. The synchronization code pattern 540 includes a
first optically transparent opening 542a followed by a series of
additional evenly spaced optically transparent openings and ending
with a last optically transparent opening 542b. Each opening in the
synchronization code pattern includes a front side (e.g., 544a) and
an end side (e.g., 544b) corresponding to the beginning and the end
of the optically transparent opening identifiable by an optical
pattern reader (e.g., including one or more light source and light
sensor combinations).
[0059] FIG. 5 also illustrates a non-limiting example of the type
of "Serial Data" signals generated by the light sensor associated
with the serial calibration code pattern 530 and the corresponding
"Synchronization" signals generated by the light sensor associated
with the serial synchronization code pattern 540. A first pulse
signal 552a of the synchronization code pattern corresponds to
exemplary first opening 542a and a last pulse signal 552b
corresponds to exemplary last opening 542b. An initial spike (e.g.,
554a) of a pulse corresponds to the optical pattern reader
identifying the front side (e.g., 544a) of a code pattern opening
and the end spike (e.g., 554b) corresponds to the optical reader
identifying the end side (544b) of the same code pattern. More
details of non-limiting exemplary aspects regarding the
synchronization and calibrations code patterns and the
correspondence between the two is depicted in FIG. 6 along with the
determination of the binary data generated from the code
patterns.
[0060] As illustrated in FIGS. 5 and 6, the sequential or serial
data coding patterns (e.g., 530) and the synchronization coding
patterns (e.g., 540) cause a series of corresponding positive
(e.g., "1") and negative (e.g., "0") code signals to be generated
by the optical read head device. These code signals are received by
the processing unit and processed in a binary form (e.g., "0" and
"1"). The code signals are received while the sensor strip is
inserted into the measurement device. The measurement device (e.g.,
an analyte meter) and sensor strip are configured to implement an
analyte analysis having at least one correlation equation
associated with a calibration code determined from the sequential
data coding patterns. A processing unit is configured to calibrate
the at least one correlation equation in response to the generated
code signals received from the optical pattern read device. The
processing unit is further configured to determine an analyte
concentration responsive to the at least one calibrated correlation
equation.
[0061] In it contemplated that the synchronization code pattern can
include anywhere from between about eight to about sixteen or more
sequential and evenly spaced optically transparent openings
disposed on a test sensor. Each of the evenly spaced
synchronization code openings (e.g., 540) corresponds to one of a
series of sequential optically transparent openings and
non-transparent positions that comprise the calibration code
pattern (e.g., 530) on the same test sensor.
[0062] Referring now to FIG. 6, a portion of a test sensor that
includes the port-insertion region is depicted, similar to the
sensor illustrated in FIG. 5 (including similar serial data and
synchronization codings). This non-limiting example of a coded test
sensor includes a series of optically transparent openings 632a,
632c, 632e, 632g, 632i that are respectively separated by optically
non-transparent portions 632b, 632d, 632f, 632h that are disposed
on the test sensor. The test sensor can be inserted into a port or
opening of an analyte meter in direction 670. As the test sensor is
inserted into the port, signals are generated by a light sensor of
an optical pattern read device. The generated signal is depicted by
the "Serial Data" illustrated in FIG. 6. As calibration code
opening 632a passes between a light source and light sensor, as
described, for example in FIG. 2, a positive signal is generated by
the light sensor in response to receiving the light beam
transmitted from the light source. The positive signal may be
interpreted in binary form as a "1" by a processor (e.g.,
microcontroller) associated with (e.g., connected to) the light
sensor or the optical pattern read device. Next, an optically
non-transparent portion 632b passes between the light source and
light sensor generating a negative signal by the light sensor as a
light beam is not received from the light source. The negative
signal may be interpreted in binary form as a "0" by the
processor.
[0063] Near simultaneous to the generation of the serial data from
the serial calibration code pattern, a corresponding
synchronization code pattern is being read and a light sensor
generates signals (e.g., "Synchronization") that act as a clocking
system for respective positions of the corresponding optically
transparent openings and optically non-transparent portions of the
calibration coding pattern. For example, optically transparent
synchronization code opening 642a is "clocked" to correspond to
optically transparent calibration code opening 632a. Optically
non-transparent synchronization portion 642b is "clocked" to
correspond to optically non-transparent calibration portion 632b.
In some aspects, the synchronization code pattern comprises a
series of similarly sized optically transparent openings that are
evenly spaced in series with a similarly sized gap of optically
non-transparent material the optically transparent openings.
[0064] Referring again to the calibration code openings for test
sensor in FIG. 6, after the optically non-transparent portion 632b
causes a generation of a negative signal, a series of calibration
positions that form optically transparent opening 632c causes a
series of positive signals to be generated by the optical pattern
read device in correspondence with clocking or synchronization
signals generated by the synchronization light sensor for the
optically transparent synchronization code openings. In the
non-limiting example of opening 632c, the generated positive
signals are interpreted by the processor in a binary form of
"1-1-1-1". This is followed by a series of calibration positions
that form another optically non-transparent portion 632d that
causes a series of negative signals to be generated by the optical
pattern read device in correspondence with clocking or
synchronization signals generated by the synchronization light
sensor for the synchronization code opening that correspond with
the series of calibration positions associated with portion 632d.
The generated negative signals are interpreted by the processor in
a binary form of "0-0-0". Similar generation of signals and
subsequent processor interpretations occur for openings 632e, 632g
632i and portions 632f, 632h in correspondence with their
respective synchronization code openings.
[0065] The number of synchronization code openings determines the
number of possible calibration codes for a test sensor. For
example, FIG. 6 includes sixteen evenly spaced synchronization code
openings (e.g., 642a) that allow for a pattern including sixteen
calibration code positions that can be either a "1" or a "0"
depending on if a positive a negative signal is generated for a
particular calibration position. This means that the maximum number
of possible calibration codes for this non-limiting embodiment is
65,536 codes (i.e., 2{circumflex over ( )}16). More or fewer
calibration codes are possible by adding or removing the number of
synchronization code openings, and thus, adding or removing the
number of calibration code positions. The number of possible
calibration codes increases and decrease exponentially (by a factor
of two in the exemplary binary aspect illustrated for the present
disclosure) for each added or removed synchronization opening.
Furthermore, while FIGS. 5 and 6 depict a generated calibration
signal corresponding to a binary calibration code of
"1011110001010001", this is just one of 65536 calibration codes
(e.g., ranging from 0000000000000000 to 1111111111111111) that can
be generated by changing the serial pattern of optically
transparent calibration openings and optically non-transparent
calibration portions comprising the calibration coding pattern on a
test sensor.
[0066] Turning now to FIGS. 7 and 8, two non-limiting exemplary
aspects of test sensors 700, 800 are depicted. Test sensors 700,
800 include optically transparent serial data coding patterns
created by punching apertures (e.g., 732, 832) into the sensor
strips. Test sensor 700, 800 also includes optically transparent
synchronization coding patterns also created by punching apertures
(e.g., 742, 842) into the sensor strip. The apertures (e.g., 732,
832) for the serial data coding can be of varying sizes that depend
on the calibration code for a sensor and whether a given position
along the calibration coding is intended to generate a positive or
negative signal. Thus, if a given aperture is coded to provide a
series of positive signals (e.g., "1-1-1"), the aperture will be
wider than an aperture that is coded to only provide a single
positive signal (e.g., "1") preceding and followed by one or more
portions intended to generate a negative signal (e.g., "0"). The
apertures (e.g., 742, 842) for the synchronization coding patterns
are generally the same size and are evenly spaced in a serial
fashion. The apertures 732, 742 in sensor 700 are generally
rectangular and are disposed entirely within the sensor 700 such
that sensor material forms a perimeter around each aperture. The
apertures 832, 842 in sensor 800 are generally square or
rectangular and are disposed along the perimeter of the sensor 800
such that sensor material only forms a partial perimeter around
each aperture. While generally rectangular shapes are depicted for
the apertures 732, 742, 832, 842, it is contemplated that other
shapes can be used as would be understood in the field of optical
pattern readers.
[0067] Turning now to FIG. 9, a sensor strip 900 is depicted
including optically transparent serial data coding patterns and
synchronization coding patterns created by placing printed coding
patterns 930, 940 on a transparent area 934, 944 of the sensor
strip. Similar to other sensors described above, the sensor strip
900 may include a port-insertion region 926 and a fluid-receiving
area 928. The port-insertion region 926 can include two sections
934, 944 of optically transparent material. A first section 934 of
optically transparent material can have a calibration overlay 930
adhered to or printed onto the optical transparent layer 934 to
form a pattern for the serial calibration coding for the sensor
strip 900. The calibration overlay 930 can have a plurality of data
openings (e.g., 932) printed, punched, or otherwise cut into the
overlay. Similarly, a second section 944 of optically transparent
material can have a synchronization overlay 940 adhered to or
printed onto the optical transparent layer 944 to form a pattern
for the serial synchronization coding for the sensor strip 900. The
synchronization overlay 940 can have a plurality of synchronization
openings (e.g., 942) printed, punched, or otherwise cut into the
overlay.
[0068] Turning now to FIG. 10, a flowchart for an exemplary method
for calibrating an analysis of an analyte in a biological fluid is
illustrated. The actions identified in the flowchart and described
below correspond to instructions that may be stored in a memory and
executed by one or more processing units within or connected to a
fluid analyte meter, such as a blood glucose meter or other types
of fluid analyte meters including portable or stationary units.
First, at step 1010, the method includes the act of transmitting
light waves through first optically transparent openings in a test
sensor that includes a first row of sequential optically
transparent and non-transparent positions forming calibration
coding patterns. Next, at step 1012, nearly simultaneous to the act
in step 1010, the act of transmitting light waves through second
optically transparent openings in the test sensor is implemented.
The transparent openings include a second row of sequential
optically transparent and non-transparent positions on the test
sensor that form synchronization coding patterns that correspond to
the calibration coding patterns. Then, at step 1014, the light
waves transmitted through the first optically transparent openings
are received by a first light sensor, and at step 1016, light waves
transmitted through the second optically transparent openings are
received by a second light sensor. Next, at step 1018, the act of
generating a series of calibration code signals is implemented in
response to light waves being received and not received by the
first light sensor. The light waves are received and not received
in response to the optically transparent and non-transparent
positions passing the first light sensor during the insertion of
the test sensor into the analyte measuring device. Then, at step
1020, nearly simultaneous to the act in step 1018, the act of
generating a series of synchronization code signals is implemented
in response to light waves being received and not received by the
second light sensor. The light waves are received and not received
in response to the second row of sequential optically transparent
and non-transparent positions passing the second light sensor
during the insertion of the test sensor into the analyte measuring
device. The series of synchronization code signals correspond to
the series of calibration code signals. Next, at step 1022, the act
of calibrating at least one correlation equation is implemented by
one or more processing units in response to the generated series of
calibration code signals. Finally, at step 1024, the act of
determining an analyte concentration is implemented by at least one
of the one or more processing units based on the at least one
calibrated correlation equation. The analyte concentration
determination further includes reacting the analyte in an
electrochemical reaction that produces an output signal. The
analyte concentration is then calculated using the at least one
calibrated correlation equation and the produced output signal.
[0069] In some aspects, it is contemplated that a method for
calibrating an analysis of an analyte in a biological fluid can
further include detecting the insertion of the test sensor into an
insertion port of an analyte meter. The detecting can occur
immediately prior to transmitting of light waves or a light beam
through optically transparent openings and non-transparent
positions forming the calibration coding patterns and the
synchronization coding patterns. It is further contemplated that
calibration coding patterns have a length where the synchronization
coding patterns are about the same length as the calibration coding
patterns. In some aspects, the second row of sequential optically
transparent and non-transparent positions are evenly spaced. The
calibration coding patterns may be disposed on the test sensor
parallel to and physically separated from the synchronization
coding patterns by an optically non-transparent portion of the
strip.
[0070] While the invention has been described with reference to
details of the illustrated embodiments, these details are not
intended to limit the scope of the invention as defined in the
appended claims. For example, although the illustrated embodiments
are generally directed to a synchronization code pattern that
includes sixteen positions or optically transparent openings,
coding patterns with more or fewer optically transparent openings,
along with different arrangements, are contemplated to provide a
clocking mechanism for the calibration code patterns. Furthermore,
different types of optically transparent openings are contemplated
including hybrids of both transparent material and partial
apertures in the test sensor material. In addition, it should be
noted that the cross-section and other geometrical aspects of the
sensor interface, light sources, light sensors, and sensors used
herein may be other shapes such as circular, square, hexagonal,
octagonal, other polygonal shapes, or oval. The non-electrical
components of the illustrated embodiments are typically made of a
polymeric material. Non-limiting examples of polymeric materials
that may be used in forming devices and strips include
polycarbonate, ABS, nylon, polypropylene, or combinations thereof.
It is contemplated that the fluid analyte systems can also be made
using non-polymeric materials. The disclosed embodiments and
obvious variations thereof are contemplated as falling within the
spirit and scope of the claimed invention.
Alternative Aspects
[0071] According to an alternative aspect A, a test sensor for
determining an analyte concentration in a biological fluid includes
a strip including a fluid-receiving area and a port-insertion
region; a first row of optically transparent and non-transparent
positions forming a calibration code pattern disposed within a
first area of the port-insertion region; and a second row of
optically transparent and non-transparent positions forming a
synchronization code pattern disposed within a second area of the
port-insertion region, the second area being different from the
first area, wherein the synchronization code pattern corresponds to
the calibration code pattern such that the synchronization code
pattern provides synchronization of the calibration code pattern
during insertion of the port-insertion region into a receiving port
of an analyte meter.
[0072] According to an alternative aspect B, the test sensor of the
preceding aspect further includes that the test sensor is an
electrochemical test sensor, the strip further including one or
more electrical contacts at least partially disposed within the
port-insertion region, the electrical contacts configured to align
and electrically connect with sensor contacts of the analyte meter
upon insertion of the port-insertion region into the receiving
port.
[0073] According to an alternative aspect C, the test sensor of any
one of preceding aspects A or B further includes that the
calibration code pattern and the synchronization code pattern
include at least one aperture in the strip, the at least one
aperture defining one or more of the optically transparent
positions.
[0074] According to an alternative aspect D, the test sensor of any
one of preceding aspects A to C further includes that the
calibration code pattern has a length, the synchronization code
pattern having the same length as the calibration code pattern.
[0075] According to an alternative aspect E, the test sensor of any
one of preceding aspects A to D further includes that the positions
forming the calibration code pattern are linearly disposed on the
strip parallel to the synchronization code pattern.
[0076] According to an alternative aspect F, the test sensor of any
one of preceding aspects A to E further includes that the
calibration code pattern is disposed on the strip parallel to and
physically separated from the synchronization code pattern by an
optically non-transparent portion of the strip.
[0077] According to an alternative aspect G, the test sensor of any
one of preceding aspects A to F further includes that the
port-insertion region includes a first edge and an opposing second
edge, the calibration code pattern being oriented parallel to and
along the first edge, the synchronization code pattern being
oriented parallel to and along the second edge.
[0078] According to an alternative aspect H, the test sensor of any
one of preceding aspects A to G further includes that the
calibration code pattern and the synchronization code pattern each
include apertures disposed in the strip along the first edge and
the second edge, each of the apertures of the code patterns being
generally rectangular with only three sides of the apertures being
defined by the strip.
[0079] According to an alternative aspect I, the test sensor of any
one of preceding aspects A to H further includes that the test
sensor includes a reagent, the reagent including glucose oxidase
and/or glucose dehydrogenase.
[0080] According to an alternative aspect J, the test sensor of any
one of preceding aspects A to I further includes that the
calibration code pattern includes between about eight and about
sixteen optically transparent first openings and the
synchronization code pattern includes between about eight and about
sixteen optically transparent second openings.
[0081] According to an alternative aspect K, the test sensor of any
one of preceding aspects A to J further includes that the
calibration code pattern occupies less than 0.04 square inches of a
top surface of the strip.
[0082] According to an alternative aspect L, the test sensor of any
one of preceding aspects A to J further includes that the
calibration code pattern occupies less than 0.02 square inches of a
top surface of the strip.
[0083] According to an alternative aspect M, the test sensor of any
one of preceding aspects A to L further includes that the
synchronization code pattern occupies less than 0.04 square inches
of a top surface of the strip.
[0084] According to an alternative aspect N, the test sensor of any
one of preceding aspects A to L further includes that the
synchronization code pattern occupies less than 0.02 square inches
of a top surface of the strip.
[0085] According to an alternative aspect O, the test sensor of any
one of preceding aspects A to N further includes that the
calibration code pattern and the synchronization code pattern
together occupy less than 0.06 square inches of a top surface of
the strip.
[0086] According to an alternative aspect P, the test sensor of any
one of preceding aspects A to N further includes that the
calibration code pattern and the synchronization code pattern
together occupy less than 0.03 square inches of a top surface of
the strip.
[0087] According to an alternative aspect Q, the test sensor of any
one of preceding aspects A to P further includes that the test
sensor is an optical test sensor.
[0088] According to an alternative aspect R, a test sensor for
determining an analyte concentration in a biological fluid includes
a strip including a fluid-receiving area and a port-insertion
region, one or more electrical contacts at least partially disposed
within the port-insertion region, the electrical contacts
configured to align and electrically connect with sensor contacts
of an analyte meter upon insertion of the port-insertion region
into a receiving port of the analyte meter; a serial calibration
code pattern disposed within a first area of the port-insertion
region, the serial calibration code pattern including first
optically transparent portions allowing light waves to be
transmitted therethrough; and a synchronization code pattern
disposed within a second area of the port-insertion region, the
second area being different from the first area, the
synchronization code pattern including second optically transparent
portions allowing light waves to be transmitted therethrough,
wherein the synchronization code pattern corresponds to the serial
calibration code pattern such that the synchronization code pattern
provides synchronization of the serial calibration code pattern
during insertion of the port-insertion region into the receiving
port of the analyte meter.
[0089] According to an alternative aspect S, the test sensor of the
preceding aspect further includes that the serial calibration code
pattern is disposed on the strip parallel to the synchronization
code pattern.
[0090] According to an alternative aspect T, the test sensor of any
one of preceding aspects R or S further includes that at least one
of the first optically transparent portions is physically separated
from another of the first optically transparent portions of the
serial calibration code pattern by an optically non-transparent
material.
[0091] According to an alternative aspect U, the test sensor of any
one of preceding aspects R to T further includes that the
synchronization code pattern has evenly distributed serial openings
each separated by evenly distributed optically non-transparent
material.
[0092] According to an alternative aspect V, the test sensor of any
one of preceding aspects R to U further includes that the test
sensor includes a reagent, the reagent including glucose oxidase or
glucose dehydrogenase.
[0093] According to an alternative aspect W, the test sensor of any
one of preceding aspects R to V further includes that the serial
calibration code pattern includes between about eight and about
sixteen optically transparent first openings and the
synchronization code pattern includes between about eight and about
sixteen optically transparent second openings.
[0094] According to an alternative aspect X, the test sensor of any
one of preceding aspects R to W further includes that the serial
calibration code pattern and the synchronization code pattern
together occupy less than 0.06 square inches of a top surface of
the strip.
[0095] According to an alternative aspect Y, the test sensor of any
one of preceding aspects R to X further includes that the serial
calibration code pattern and the synchronization code pattern
together occupy less than 0.03 square inches of a top surface of
the strip.
[0096] According to an alternative aspect Z, a biosensor system for
determining an analyte concentration in a biological fluid includes
a measurement device including a processing unit connected to an
optical pattern read device, the optical pattern read device
including one or more light sources, a first light sensor, and a
second light sensor, and a sensor strip including sequential data
coding patterns including first optically transparent openings and
separate corresponding synchronization coding patterns including
second optically transparent openings, wherein the one or more
light sources are configured to transmit light waves through the
first and second optically transparent openings, the one or more
light sources being at least partially positioned on a first side
of the first and second optically transparent openings, wherein the
first light sensor is positioned on an opposite side of the first
optically transparent openings and the second light sensor is
positioned on an opposite side of the second optically transparent
openings, the first light sensor and the second light sensor
configured to receive transmitted light waves from the one or more
light sources, wherein the light waves are transmitted by the one
or more light sources and received by the first light sensor and
the second light sensor while the sensor strip is being inserted
into the measurement device such that light waves received by the
second light sensor associated with the synchronization coding
patterns provide synchronization for the light waves received by
the first light sensor associated with the sequential data coding
patterns.
[0097] According to an alternative aspect AA, the biosensor of the
preceding aspect further includes that the sequential data coding
patterns and the synchronization coding patterns cause a series of
corresponding positive and negative code signals to be generated by
the optical pattern read device and received by the processing unit
while the sensor strip is inserted into the measurement device, the
measurement device and sensor strip being configured to implement
an analyte analysis having at least one correlation equation
associated with the sequential data coding patterns, the processing
unit configured to calibrate the at least one correlation equation
in response to the generated code signals received from the optical
pattern read device, the processing unit further configured to
determine an analyte concentration responsive to the at least one
calibrated correlation equation.
[0098] According to an alternative aspect AB, the biosensor of any
one of preceding aspects Z or AA further includes that the
sequential data code patterns include between eight and sixteen
sequential first optically transparent openings, and wherein the
synchronization coding patterns include between eight and sixteen
sequential and evenly spaced second optically transparent
openings.
[0099] According to an alternative aspect AC, the biosensor of any
one of preceding aspects Z to AB further includes that at least a
portion of the sequential data coding patterns are apertures in the
sensor strip.
[0100] According to an alternative aspect AD, the biosensor of any
one of preceding aspects Z to AC further includes that at least a
portion of the synchronization coding patterns are apertures in the
sensor strip.
[0101] According to an alternative aspect AE, the biosensor of any
one of preceding aspects Z to AD further includes that the
sequential data coding patterns are distributed along a length of
the sensor strip, the synchronization coding patterns having the
same length as the sequential data coding patterns.
[0102] According to an alternative aspect AF, the biosensor of any
one of preceding aspects Z to AE further includes that the
sequential data coding patterns are disposed on the sensor strip
parallel to the synchronization coding patterns.
[0103] According to an alterative aspect AG, the biosensor of any
one of preceding aspects Z to AF further includes that the
synchronization coding patterns are evenly distributed optically
transparent sequential openings on a surface of the sensor strip
such that each adjacent optically transparent synchronization
opening is separated by an optically non-transparent material.
[0104] According to an alternative aspect AH, the biosensor of any
one of preceding aspects Z to AG further includes that the
sequential data coding patterns and the synchronization coding
patterns are parallel and physically separated by a portion of the
surface of the sensor strip along the entire length of the
respective coding patterns.
[0105] According to an alternative aspect AI, the biosensor of any
one of preceding aspects Z to AH further includes that the sensor
strip has a first edge and an opposing second edge, the sequential
data coding patterns being sequentially positioned along the first
edge and the synchronization coding patterns being sequentially
positioned along the opposing second edge.
[0106] According to an alternative aspect AJ, the biosensor of any
one of preceding aspects Z to AI further includes that the
sequential data coding patterns and the synchronization coding
patterns include one or more apertures in the sensor strip, each
coding pattern aperture being rectangular and defined along only
three sides by optically non-transparent material of the sensor
strip.
[0107] According to an alternative aspect AK, the biosensor of any
one of preceding aspects Z to AJ further includes that the
biosensor includes a reagent, the reagent including glucose oxidase
or glucose dehydrogenase.
[0108] According to an alternative aspect AL, the biosensor of any
one of preceding aspects Z to AK further includes that the one or
more light sources includes a single LED light and two light guides
for receiving light from the LED light and redirecting the light
waves to the first optically transparent openings and the second
optically transparent openings, the light waves being directed by
total internal reflection within the two light guides, the two
light guides being configured to emit light beams narrower than the
smallest dimension of the optically transparent openings.
[0109] According to an alternative aspect AM, the biosensor of any
one of preceding aspects Z to AL further includes that the one or
more light sources includes a two LED lights, one LED light being
positioned to transmit light waves through the first optically
transparent openings and into the first light sensor, the other LED
light being positioned to transmit light waves through the second
optically transparent openings and into the second light
sensor.
[0110] According to an alternative aspect AN, the biosensor of any
one of preceding aspects Z to AM further includes that each of the
one of more light sources includes a mask configured such that the
one or more light sources emit a light beam narrower than the
smallest dimension of the optically transparent openings.
[0111] According to an alternative aspect AO, the biosensor of any
one of preceding aspects Z to AN further includes that the light
sensors generate a sequence of pulses in response to the light
waves being transmitted through the first optically transparent
openings associated with the sequential data coding patterns and
the second optically transparent openings associated with the
synchronization coding patterns.
[0112] According to an alternative aspect AP, the biosensor of any
one of preceding aspects Z to AO further includes a sensor strip
detection system for detecting the sensor strip being inserted into
a port of the measurement device, wherein the sensor strip is
detected immediately prior to commencing the optical reading of the
sequential data coding patterns and the synchronization coding
patterns.
[0113] According to an alternative aspect AQ, a method for
determining an analyte concentration in a biological fluid using a
calibrated correlation equation includes the following acts: (a)
transmitting light waves through first optically transparent
openings in a test sensor including a first row of sequential
optically transparent and non-transparent positions forming
calibration coding patterns; (b) near simultaneous to act (a),
transmitting light waves through second optically transparent
openings in the test sensor including a second row of sequential
optically transparent and non-transparent positions forming
synchronization coding patterns that correspond to the calibration
coding patterns; (c) receiving the light waves transmitted through
the first optically transparent openings in a first light sensor;
(d) receiving the light waves transmitted through the second
optically transparent openings in a second light sensor; (e)
generating a series of calibration code signals in response to
light waves being received and not received by the first light
sensor due to the optically transparent and non-transparent
positions passing the first light sensor during the insertion of
the test sensor into an analyte measuring device; (f) near
simultaneous to act (e), generating a series of synchronization
code signals in response to light waves being received and not
received by the second light sensor due to the optically
transparent and non-transparent positions passing the second light
sensor during the insertion of the test sensor into the analyte
measuring device, the series of synchronization code signals
corresponding to the series of calibration code signals; (g)
calibrating at least one correlation equation in response to the
generating the series of calibration code signals; and (h)
determining an analyte concentration based on the at least one
calibrated correlation equation, wherein the analyte concentration
is determined by reacting the analyte in a reaction that produces
an output signal, the analyte concentration being determined using
the at least one calibrated correlation equation and the produced
output signal.
[0114] According to an alternative aspect AR, the method of the
preceding aspect further includes detecting the insertion of the
test sensor into an insertion port of an analyte meter, the
detecting occurring immediately prior to the transmitting of light
waves in steps (a) and (b).
[0115] According to an alternative aspect AS, the method of any one
of preceding aspects AQ or AR further includes that the calibration
coding patterns have a length, the synchronization coding patterns
having the same length as the calibration coding patterns.
[0116] According to an alternative aspect AT, the method of any one
of preceding aspects AQ to AS further includes that the second row
of sequential optically transparent and non-transparent positions
are evenly spaced.
[0117] According to an alternative aspect AU, the method of any one
of preceding aspects AQ to AT further includes that the calibration
coding patterns are disposed on the test sensor parallel to and
physically separated from the synchronization coding patterns by an
optically non-transparent portion of the strip.
[0118] According to an alternative aspect AV, the method of any one
of preceding aspects AQ to AU further includes that the test sensor
is for determining blood glucose concentration.
[0119] According to an alternative aspect AW, the method of any one
of preceding aspects AQ to AV further includes that at least a
portion of the sequential optically transparent and non-transparent
positions are linearly arranged.
[0120] According to an alternative aspect AX, the method of any one
of preceding aspects AQ to AW further includes that at least a
portion of the sequential optically transparent and non-transparent
positions are staggered.
[0121] According to an alternative aspect AY, the method of any one
of preceding aspects AQ to AX further includes that the reaction is
an electrochemical reaction and the output signal is an electric
signal.
[0122] Each of these embodiments and obvious variations thereof is
contemplated as falling within the spirit and scope of the claimed
invention, which is set forth in the following claims. Moreover,
the present concepts expressly include any and all combinations and
subcombinations of the preceding elements and aspects.
* * * * *